A4J40 - 40 Amp Fuse

A4J40 - 40 Amp Fuse

Electrical problems don’t usually come with a warning, which is why having dependable circuit protection matters. The Mersen A4J40 Amp-Trap® Class J Fast-Acting Fuse is designed to respond quickly when overloads or short circuits happen, helping you protect valuable equipment before serious damage occurs. Rated at 40 amps, this fuse is commonly used in commercial and industrial electrical systems where reliability, safety, and minimizing downtime are all important.

The A4J40 uses fast-acting current-limiting technology to help you reduce the amount of fault energy passing through the circuit. That quick response can help protect motors, control panels, HVAC equipment, lighting systems, and other sensitive electrical components from unnecessary stress during fault conditions. In busy facilities where your equipment uptime matters, dependable overcurrent protection can make a big difference in day-to-day operations.

Another benefit is the Class J rejection-style design, which helps prevent lower-rated fuses from being installed by mistake. That added layer of protection supports safer maintenance practices and helps maintain proper system protection.

Key Features and Benefits

• 40 amp Class J fast-acting fuse: Designed for dependable overcurrent protection.
• Rapid response during overloads and short circuits: Helps reduce equipment damage.
• Current-limiting design: Helps reduce fault energy.
• Improves protection for motors, panels, and electrical systems: Supports reliable circuit protection.
• Class J rejection-style construction: Helps prevent incorrect replacement.
• High 200 kA interrupting rating: Designed for demanding fault-current conditions.
• Suitable for AC and DC applications: Supports commercial and industrial electrical systems.
• Ferrule terminal design: Provides secure installation.
• Tin-plated copper terminals: Provide reliable conductivity.
• Durable PolyTube body: Designed for industrial and commercial environments.
• ROHS compliant: Supports environmental compliance requirements.
  

Technical Specifications

• Manufacturer: Mersen
  
• Catalog Number: A4J40
  
• Series: Amp-Trap® A4J
  
• Fuse Class: Class J
  
• Fuse Type: Fast-Acting
  
• Amp Rating: 40A
  
• Voltage Rating: 600VAC / 300VDC
  
• Frequency: 50/60 Hz
  
• Interrupting Rating: 200 kA AC
  
• Current Type: AC/DC
  
• Mounting Style: Clip
  
• Terminal Type: Ferrule
  
• Terminal Material: Tin-Plated Copper
  
• Body Material: PolyTube
  
• Product Diameter: 27 mm
  
• Product Length: 60.5 mm
  
• Product Weight: 0.0771 kg
  
• UPC/EAN: 782001960223
  

Material Compliance and Certifications

• ROHS Compliant: Designed to support environmental compliance requirements.
• Low Voltage UL/CSA Applications: Designed for Low Voltage UL/CSA fuse applications.
• Suitable for commercial and industrial electrical systems: Designed for dependable overcurrent protection.
  

Where It Works Best

• The A4J40 works well in industrial machinery, HVAC systems, lighting panels, motor control circuits, branch circuits, OEM equipment, and electrical distribution systems where fast overcurrent protection is important. It is especially useful in applications that require quick fault interruption to help reduce equipment damage and unplanned downtime.